Flexible spine binder



FIG. 1 is a perspective view of a flexible spine binder showing the front cover thereof;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a bottom plan view; and,

FIG. 6 is a top plan view. 

The ornamental design for a flexible spine binder, as shown. 